Modal Verbs

Modal Verbs

1. Ability

   • -
     • couldn't = wasn't/ weren't able to
   • + / ?
     • can = be able to
       • present
       • current deccision
     • will be able to
       • future
     • could = used to be able to = was/were able to
       • repeated past
     • was/were able to = manage to
       • single past
     • could
       • + see, hear, smell, taste, feel, understand, guess, remember

2. Obligation/ Duty/ Necessity

   • +/?
     • must
       • it's your duty/ you're obliged to do sth
         • speaker's decission
     • have (got) to
       • it's necessary to do sth
         • someone else's decission
     • should/ ought to
       • less emphatic than must
     • need = it's necessary to
   • - (absence od necessity)
     • need't/don't need to/don't have to = it isn't necessary to
       • present/ future
     • didn't need to/didn't have to = it wasn't necessary to
       • an action didn't happen
     • needn't have done = it wassn't necessary to
       • an action did happen
   • ?
     • must I = do you insist that I
     • do I have to = is it necessary for me to

3. Prohibition

   • -
     • mustn't/can't = you're not allowed to/ it's forbidden to/ it's against rules to

4. Logical Assumptions

   • must = it's certainly true
   • can't/ couldn't = it's certainly not true

5. Probability

   • should/ ought to = probably
     • sth's likely to happen in the present/ future

6. Possibility

   • +/?
     • can = general possibility
       • it's theoretically possible/ in general, not referred to a specific situation
     • could/may/might = perhaps/ it's likely to/ it's possible to
       • sth's likely to happen in a specific situation
     • could have been/might have been = it was possible but didn't happen
       • past
   • ?
     • can (general or specific)/could/might
     • DO NOT USE MAY

7. Permission

   • Asking for permission
     • can/could/may/might I ...? = do you/ would you mind if I ...?
       • could/ may - more polite than can
       • might - formal
       • may/might - we do not know the person
       • can/could - we know the prerson well
   • Giving permission
     • can/may = you are allowed to
       • can - informal
       • may - formal
   • Refusing permission
     • can't/mustn't/may not = you're not allowed to
       • may not - formal
   • Talking about permission
     • +/?
       • can/ be allowed to
         • refer to laws or regulation
       • could/was/were allowed to
         • we had general permission in the past
       • was/ were allowed to
         • we had permission in a particular situation in the past
     • ?
       • may I = will you allow me to
       • am I allowed to = what's the rule?

8. Offers

   • I'll = I'm willing to
   • Shall/Can/Could I/we = would you like me/ us to

9. Requests

   • can/could/would/will you ...?
     • ask sb to do sth for us
     • can/will - informal
     • would/could - more polite
   • may/might/can/could I ...?
     • ask for sth politely
     • might - formal, not often used

10. Suggestions

    • shall I/we ...? = why don't we ...?/ how about ...?
      • ask for suggestions or instructions
    • I/we can/could = what about ...?/let's ...

11. Advise

    • should/ought to = I advise you to/ you had better
      • polite advise, doesn't need to be followed
    • must
      • strong advise, has to be followed

12. Criticism

    • should have/ought to have = it would have been better if you had...

13. Expressions similar to modal verbs

    • be supposed to = should
      • sb expects us to do sth
    • be to = must
      • give orders
    • be likely to/ it's likely that = probably
      • more emphatic than may but less than should/ought to